SECTION 01 FileUpload 总览
在编写网站程序的时候, client 与 server 之间的往往不只有纯文字的沟通, 还会有 binary 的文件传输, 该如何在 HTML Form 之中传送, 就要遵守
RFC 1867 的规范了.
基本上, post.jsp (选择文件)应该都会有下面类似的 html tag :
<form action="upload.jsp" enctype="multipart/form-data" method="POST">
input your name: <input type="text" name="name"> <br>
select the file: <input type="file" name="file"> <br>
<input type="submit" value="submit">
</form>
这一部份是属于 HTML 的范畴, 有兴趣的可以钻研 RFC ...
SECTION 02 multipart/form-data 的 HTTP 表现情形
当你按下传送的时候, Browser 将会送出 Post 的资料到 server,
POST http://localhost:9000/fileupload/upload.jsp HTTP/1.1
Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/vnd.ms-powerpoint, application/vnd.ms-excel, application/msword, */*
Referer: http://localhost:9000/fileupload/post.jsp
Accept-Language: zh-tw,zh-cn;q=0.7,en-us;q=0.3
Content-Type: multipart/form-data; boundary=---------------------------7d33e580784
Accept-Encoding: gzip, deflate
User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)
Host: www.softleader.com.tw
Content-Length: 3020
Connection: Keep-Alive
Cache-Control: no-cache
Cookie: JSESSIONID=3B31F07F56328E7B623A9BA1C4E3479D
我们可以知道, Contenet-Type 是用 multipart/form-data 另外还有 boundary 的传输.
SECTION 03 实际的例子 File.html by 林上杰
<html>
<head>
<title>File Upload</title>
<meta http-equiv="Content-Type" content="text/html; charset=big5">
</head>
<body bgcolor="#FFFFFF" text="#000000"><p><font size="5"color="#FF0000">
<b>第七章 文件上传范例</b></font></p>
<form name="Form1" enctype="multipart/form-data" method="post" action="JYFile.jsp">
<p>上传文件 1： <input type="file"name="File1" size="20" maxlength="20"> </p>
<p>文件1叙述： <input type="text" name="File1" size="30" maxlength="50"> </p>
<p>上传文件 2： <input type="file" name="File2" size="20" maxlength="20"> </p>
<p>文件2叙述： <input type="text" name="File2" size="30" maxlength="50"> </p>
<p>上传文件3： <input type="file" name="File3" size="20" maxlength="20"> </p>
<p>文件3叙述： <input type="text" name="File3" size="30" maxlength="50"> </p>
<p> <input type="submit"value="上传"> <input type="reset" value="清除"> </p>
</form>
</body>
</html>
SECTION 04 传送格式
POST /newspaper/JYFile.jsp HTTP/1.1
Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg,
application/vnd.ms-powerpoint, application/vnd.ms-excel, application/msword, */*
Referer: http://localhost:9000/newspaper/JYFile.html
Accept-Language: zh-tw,zh-cn;q=0.7,en-us;q=0.3
Content-Type: multipart/form-data; boundary=---------------------------7d31091c6205fc
Accept-Encoding: gzip, deflate
User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)
Host: localhost:9000
Content-Length: 428583
Connection: Keep-Alive
Cache-Control: no-cache
Cookie: JSESSIONID=E141744815A8FF44F8AA9BA6D5946710
-----------------------------7d31091c6205fc
Content-Disposition: form-data; name="File1"; filename="C:\test\测试.exe"
Content-Type: application/octet-stream
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX ( binary 乱码 )
-----------------------------7d31091c6205fc
Content-Disposition: form-data; name="File1"
exe
-----------------------------7d31091c6205fc
Content-Disposition: form-data; name="File2"; filename="C:\test\测试.gif"
Content-Type: image/gif
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX ( binary 乱码 )
-----------------------------7d31091c6205fc
Content-Disposition: form-data; name="File2"
gif
-----------------------------7d31091c6205fc
Content-Disposition: form-data; name="File3"; filename="C:\test\测试.xls"
Content-Type: application/vnd.ms-excel
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX ( binary 乱码 )
-----------------------------7d31091c6205fc
Content-Disposition: form-data; name="File3"
xls
-----------------------------7d31091c6205fc--
SECTION 05 送到 JYFile.jsp 上传处理 by JiaYun
<%@ page contentType="text/html;charset=Big5" language="java" %>
<%@ page import="java.io.*" %>
<%@ page import="java.util.*" %>
<%@ page import="org.apache.commons.fileupload.*" %>
<%
// 申明将上传文件放到服务器的 / .... /upload 目录中
String saveDirectory = "c:\\";
// 申明临时目录
String tmpDirectory = "c:\\";
// 申明限制上传文件总大小为, 单位为 byte, -1 表示无限制
int maxPostSize = 1024 * 1024;
%>
<%
// 申明储存叙述上传文件内容的变量
String FileDescription = null;
// 申明储存上传文件名称的变量
String FileName = null;
// 申明储存上传文件大小的变量
long FileSize = 0;
// 申明储存上传文件类型的变量
String ContentType = null;
// 计算上传文件之个数
int count = 0 ;
%>
<%
DiskFileUpload upload = new DiskFileUpload();
// 设置内存存放数据的大小, 超过则写入文件, 有设定临时目录, 临时文件置于临时目录下
upload.setSizeThreshold(4096);
// 设置总上传大小限制
upload.setSizeMax(maxPostSize);
// 设置临时目录
upload.setRepositoryPath(tmpDirectory);
List /* FileItem */ items = upload.parseRequest(request);
%>
<body>
<%
Iterator iter = items.iterator();
int tmp = 0;
FileItem tmpItem = null;
while (iter.hasNext())
{
tmp++;
FileItem item = (FileItem) iter.next();
if (item.isFormField()) {
// 如果是一般栏位, 取得文件叙述
FileDescription = item.getString();
} else {
// 否则取得文件信息
FileName = item.getName();
// 因为不同的浏览器会造成传递 path + filename, 有些则只有 filename
try {
// for wintel platform
FileName = FileName.substring(FileName.lastIndexOf("\\")+1);
// for unix-like platform
FileName = FileName.substring(FileName.lastIndexOf("/")+1);
} catch ( Exception ex ) {
out.println(ex);
}
ContentType = item.getContentType();
FileSize = item.getSize();
tmpItem = item;
}
// 因为一个文件都是两个栏位, 每读取两个栏位处理一次
if (tmp == 2 && FileSize != 0)
{
count ++;
%>
<font color="red">你上传的第<%= count %>个的文件：</font><br>
文件名称为：<%= FileName %><br>
文件大小为：<%= FileSize %> Bytes<br>
文件类型为：<%= ContentType %><br>
文件的叙述：<%= FileDescription %><br><br>
<%
// 将文件写入存档目录
try {
out.println(FileName);
File uploadedFile = new File(saveDirectory + FileName);
tmpItem.write(uploadedFile);
} catch ( Exception ex ) {
out.println(ex);
}
tmp = 0;
} else if (tmp == 2 && FileSize == 0) {
tmp = 0;
} // end if
} // end while
%>
您总共上传<font color="red"><%= count %></font>个文件
</body>
</html>
家芸妹妹把注解说明的很清楚了, 有心的人就仔细查阅吧 ~~~
SECTION 06 Struts FileUpload
为何 struts 1.1 要等 Commons-FileUpload 1.0 呢
因为 struts 有一个 subpackage 叫做 org.apache.struts.upload.*; 这里面就是设定相关的 file 格式如果你使用 struts 为 MVC Framework 就可以参考 example 中的 struts-upload.war 的开发
(1) 建立 upload.jsp
<html:form action="upload.do?queryParam=Successful" enctype="multipart/form-data">
文件叙述:<html:text property="theText" /><br>
选择文件:<html:file property="theFile" /><br>
</html:form>
(2) 建立 UploadForm.java
public class UploadForm extends ActionForm{
..........
public String getTheText() {
return theText;
}
public void setTheText(String theText) {
this.theText = theText;
}
public FormFile getTheFile() {
return theFile;
}
public void setTheFile(FormFile theFile) {
this.theFile = theFile;
}
..........
}
请注意 FormFile 是建立在 org.apache.struts.upload 这个 package 中的
(3) 编写 UploadAction
public ActionForward execute(ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response){
UploadForm theForm = (UploadForm) form;
String text = theForm.getTheText();
FormFile file = theForm.getTheFile();
String fileName= file.getFileName();
String contentType = file.getContentType();
String size = (file.getFileSize() + " bytes");
.... // 看你要如何处理
.... // 可以用 InputStream 取得 file.getInputStream 等等
return mapping.findForward("ThePageYouWannaGo");
}
(4) 建立 struts-config.xml
<form-beans>
<form-bean name="uploadForm"
type="org.apache.struts.webapp.upload.UploadForm" />
</form-beans>
<action-mappings>
<!-- Upload Action -->
<action path="/upload" type="org.apache.struts.webapp.upload.UploadAction"
name="uploadForm" scope="request" input="/upload.jsp">
<forward name="display" path="/display.jsp" />
</action>
详细内容请下载 struts 1.1 src 查阅内容
SECTION 06 总结
其实大家熟悉的都是 Oreilly MultiPartRequest 和 jspsmart的SmartUpload , 请参考 jsptw 的 browser 所写的著作.
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